DESCRIPTION: This application proposes to test the hypothesis that reduction of oral tumor cell EGF receptor mRNA can lead to inhibition of tumor cell growth. There are two specific aims proposed to test the stated hypothesis. Aim 1 proposes to construct an inducible and stable vector for ribozyme expression. Aim 2 proposes to test ribozyme inhibition of EGFR expression at the RNA and protein levels and to test their effects on the transformed phenotype of oral cancer cells which overexpress EGFR.